#include<iostream>
#include<vector>
#include<queue>
#include<cstring>
#include<cmath>
#include<map>
#include<set>
#include<cstdio>
#include<algorithm>
#define debug(a) cout<<#a<<"="<<a<<endl;
using namespace std;
const int maxn=400;
typedef long long LL;
typedef pair<LL,LL> P;
inline LL read(){LL x=0,f=1;char ch=getchar();	while (!isdigit(ch)){if (ch=='-') f=-1;ch=getchar();}while (isdigit(ch)){x=x*10+ch-48;ch=getchar();}
return x*f;}
map<LL,LL>map1,map2;
P a[maxn];
int main(void){
   	cin.tie(0);std::ios::sync_with_stdio(false);
    LL n;cin>>n;
    for(LL i=1;i<=n;i++){
        cin>>a[i].first>>a[i].second;
    }
    LL ans=n*(n-1)*(n-2)/6;
    for(int i=1;i<=n;i++){
        for(int j=i+1;j<=n;j++){
            for(int k=j+1;k<=n;k++){
                if((a[i].second-a[j].second)*(a[k].first-a[j].first)==(a[k].second-a[j].second)*(a[i].first-a[j].first))
                    ans--;
            }
        }
    }
    cout<<ans<<endl;
   	return 0;
}
